<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title>1-标准流-浮动-定位的层级关系</title>
		<style type="text/css">
			*{
				margin:0;
				padding:0;
			}
			div{
				width:200px;
				height:200px;
			}
			.red{
				background: red;
			}
			.orange{
				background:orange;
				float:left;
			}
			.blue{
				background: #0000FF;
				position: relative;
			}
		</style>
	</head>
	<body>
		<div class="red"></div>
		<div class="orange"></div>
		<div class="blue"></div>
	</body>
</html>
